1. Field of the Invention
This invention relates to means for stabilizing a satellite against torques developed by solar pressure on solar panels and more particularly to a magnetic torquing device capable of compensating for the solar pressure torque developed on an asymmetric externally mounted solar panel.
2. Description of the Prior Art
The use of solar panels to convert solar energy into electrical energy on space satellites is well known. The solar pressure acting on the surface of the solar panels creates a torque which, if not balanced, will tend to displace or rotate a satellite from a dynamically stabilized position or orientation. Techniques such as the use of propulsion torquing or magnetic torquing have been used to develop torques to compensate for those created by the solar pressure. Satellites are being required to provide greater numbers of sensors facing earthward and skyward for ecological, surveillance, navigational, and stabilization purposes. These additional sensors place constraints on the organization of a satellite to preclude the use of balanced or symmetrically arranged solar panels. Such balanced arrays are usually in the form of a pair of solar panels extending from the satellite in a symmetrical arrangement. Large satellites requiring large solar-sourced electrical power will need still more solar cells. The use of solar panels that are body-mounted on the surface of the satellite are not adequate. It appears, thus, that only by extending the exposed surface of the solar array can the increased power requirements be met. The constraints of requiring more body-mounted sensor exposure limits the freedom of utilizing symmetrical arrays.
An asymmetrical array, regardless of size, produces a secular momentum accumulation which must be periodically or continuously removed. Providing increased solar energy power while meeting the constraints of more sensors that preclude geometrically symmetrical and balanced solar panels requires a single asymmetrical and thus unbalanced solar panel extending from the satellite in such an orientation as not to interfere with the viewing path of sensors mounted on the spacecraft. To provide such a single panel solar array without extensive alterations in the satellite structure and control system is a problem that exists in the art of attitude control.